export default {
  
  
  
  
  
  
  // 为当前模块开启命名空间
  namespaced: true,

  // 模块的 state 数据
  state:{
    cart: JSON.parse(uni.getStorageSync('cart') || '[]')
  },
  // state: () = > ({
  //   // 购物车的数组，用来存储购物车中每个商品的信息对象
  //   // 每个商品的信息对象，都包含如下 6 个属性：
  //   // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
  //   cart: [],
  // }),
    
  // 模块的 mutations 方法
  mutations: {
    addToCart(state, goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      // console.log(findResult)
      if(!findResult){
        state.cart.push(goods)
      }else{
        findResult.goods_count ++
      }
      this.commit('m_cart/saveToStorage')
      // console.log(state.cart)
    },
    //持久化存储，存储到本地
    saveToStorage(state){
      uni.setStorageSync('cart', JSON.stringify(state.cart))
    },
    //更新购物车中商品的勾选状态
    updateGoodsState(state, goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if(findResult){
        findResult.goods_state = goods.goods_state
        this.commit('m_cart/saveToStorage')
      }
    },
    //更新商品数量
    updateGoodsCount(state, goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if(findResult){
        findResult.goods_count = goods.goods_count
        //持久化存储
        this.commit('m_cart/saveToStorage')
      }
    },
    //根据id删除购物车中的商品
    removeGoodsById(state, goods_id){
      state.cart = state.cart.filter(x => x.goods_id !== goods_id)
      this.commit('m_cart/saveToStorage')
    },
    //更新所有商品的勾选状态
    updateAllGoodsState(state, newState){
      state.cart.forEach(x => x.goods_state = newState)
      this.commit('m_cart/saveToStorage')
    },
  },

  // 模块的 getters 属性
  getters: {
    // 动态统计购物车商品中的总数量
    total(state){
      return state.cart.reduce((total, item)=>total += item.goods_count,0)
      // let c = 0
      // //循环统计商品的数量，累加到变量c中
      // state.cart.forEach(goods => c += goods.goods_count)
      // return c
    },
    //勾选商品的总数量
    checkedCount(state){
      return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count, 0)
    },
    //已勾选商品的总价格
    checkedGoodsAmount(state){
      return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count * item.goods_price, 0).toFixed(2)
    },
  },
}